#main{
	width: 408px;
	height:408px;
	background:white;
	border:2px solid gray;
	margin:0 auto;
	overflow: hidden;
}

h2{
	text-align: center;
}

#con{
	width:100%;
	height: 400px;
	position: relative;
	top: -400px;
	border-collapse: collapse;
}

.row{
	height: 100px;
	width: 100%;
}

.cell{
	height: 100px;
	width: 100px;
	float: left;
	border:rgb(54,74,129) 1px solid;
}
.black{
	background: black;
}

.btn{
	width: 100%;
	text-align: center;
}

.start{
	margin-top: 20px auto;
	width: 150px;
	height:50px;
	border-radius: 10px;
	background: yellowgreen;
	line-height: 50px;
	color: #fff;
}